645779 divided by 20 
We want to figure out the number of times 645779 can be divided by 20.

On to step 1:
The number 20 fits into 6 0 times, leaving a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 20

Step 2:
20 can be fit into 64 3 times, resulting in a remainder of 4.
Write down 3 as next digit of the result. 
Result so far: 3.0
If we subtract 60 from 64, we get 4.
Grab the next digit (5) from the dividend, add it to 4, then carry on: 45 / 20

Step 3:
20 can be fit into 45 2 times, resulting in a remainder of 5.
Write down 2 as next digit of the result. 
Result so far: 32.0
Subtracting 40 from 45 leaves us with 5.
Bring next digit (7) of the dividend behind the 5 and repeat the process: 57 / 20

Step 4:
57 divided by 20 is 2 with a remainder of 17.
Put 2 as the next digit of the answer. 
Result so far: 322.0
If we take 40 away from 57, we end up with 17.
Include the next digit (7) from the dividend after 17, then repeat: 177 / 20

Going ahead to step 5:
20 goes into 177 8 times with a remainder of 17.
Write down 8 as next digit of the result. 
Result so far: 3228.0
If we take 160 away from 177, we end up with 17.
Grab the next digit (9) from the dividend, add it to 17, then carry on: 179 / 20

Going ahead to step 6:
20 can be fit into 179 8 times, resulting in a remainder of 19.
Record the quotient 8 as the next digit in the result. 
Result so far: 32288.0
If we subtract 160 from 179, we get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 7:
When dividing 190 by 20, we get 9 with a remainder of 10.
Put 9 as the next digit of the answer. 
Result so far: 32288.9
If we subtract 180 from 190, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 8:
100 divided by 20 is 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 32288.95
Deduct 100 from 100 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
20 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 32288.95
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 10:
0 divided by 20 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 32288.95
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 32288.95, and the remainder is 0.0.